Her husband of 23 years, Brian, said: "Anybody who has met Diane and wishes to pay their final respects is more than welcome."
The motor-neurone-disease sufferer died at a hospice near her Luton home after losing a protracted court battle to enable her husband to help her end her life.
She feared the choking and asphyxia often caused by her disease.
The 43-year-old started having breathing difficulties three days after she lost her battle in the European Court of Human Rights.
She died after slipping into a coma following 10 days of severe breathing difficulties caused by the advanced state of her condition.
Mr Pretty, who was at his wife's bedside when she died, said: "Diane had to go through the one thing she had foreseen and was afraid of - and there was nothing I could do to help."
On her website, the mother-of-two had written: "I want to have a quick death without suffering, at home surrounded by my family so that I can say goodbye to them."
Supporters wishing to attend the funeral can contact the Voluntary Euthanasia Society for more details by e-mailing tamora@ves.org.uk.